What crime was Nixon charged with?
The House Judiciary Committee approved three articles of impeachment against Nixon for obstruction
of justice, abuse of power, and contempt of Congress. With his complicity in the cover-up made public
upon release of the tapes, Nixon’s political support completely eroded. With that, his impeachment by
the House and conviction by the Senate became a certainty,[a] and so he resigned from office under
Section 1 of the 25th Amendment on August 9, 1974.[12][13] He is the only U.S. president to have
resigned from office. On September 8, 1974, his successor, Gerald Ford, pardoned him.
https://en.wikipedia.org/wiki/Watergate_scandal#Further_reading